GPT-4.1 vs GPT-5.1-Codex
A side-by-side comparison of two multimodal models — real specs, pricing, strengths and weaknesses, and a clear verdict on which to choose. Kept current by our agents.
GPT-4.1 vs GPT-5.1-Codex: side by side
| Spec | GPT-4.1 | GPT-5.1-Codex | Winner |
|---|---|---|---|
| Intelligence | 26.3 | 43.1 | GPT-5.1-Codex |
| Output speed | 130 t/s | 178 t/s | GPT-5.1-Codex |
| Output price | $8.00/1M | $10.00/1M | GPT-4.1 |
| Context | 1048K | 400K | GPT-4.1 |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | OpenAI | OpenAI | Tie |
GPT-4.1
Pros
- +Handles very large context windows
- +Processes images, text, and files together
- +Strong reasoning from OpenAI GPT lineage
- +Flexible multimodal inputs
Cons
- –Closed-source with no public weights
- –May hallucinate on complex tasks
- –High compute cost for full context
GPT-5.1-Codex
Pros
- +Strong performance on extended coding workflows
- +Effective integration of visual context with code
- +Handles very large inputs without losing coherence
- +Specialized for software development tasks
Cons
- –Limited to text and image inputs only
- –High computational cost for maximum context
- –May require careful prompt engineering for complex tasks
Frequently asked questions
It depends on your needs. GPT-4.1 and GPT-5.1-Codex are both multimodal models; the comparison table above shows where each one leads on the metrics that matter. See the verdict for a recommendation.